Tab order is important for proper navigation through a keyboard interface. The keyboard tab order must be coordinated with the structure of the webpage.
An index is a link but an internal link meaning in a Word document you can jump around a document much like you can link in a website from one page to another or even from one section to another section.
In an earlier video Calum came across "Read More Buttons" on article summaries and it proved really annoying and frustrating as it was repeated each time.
How People with Disabilities Use Links. While screen readers can read a full page to a user, screen reader users may prefer to instead listen to a list of links.
Several factors can create barriers for audiences with disabilities, particularly those who are deaf, hard of hearing, blind, severely sight impaired or visually impaired.